package string;

public class StringBuilderDemo {
    public static void main(String[] args) {




        String str="好好学习Java";
        StringBuilder builder=new StringBuilder(str);
        //append():追加内容---在末尾追加
        builder.append(",为了找个好工作");
        System.out.println(builder); //好好学习Java,为了找个好工作

        //replace():替换部分内容(含头不含尾)
        builder.replace(9,16,"就是为了改变世界");//好好学习Java,就是为了改变世界
        System.out.println(builder);

        //delete():删除部分内容(含头不含尾)
        builder.delete(0,9);
        System.out.println(builder); //就是为了改变世界

        //insert():插入内容
        builder.insert(0,"活着，"); //活着，就是为了改变世界




        System.out.println(builder);




        /*
        //StringBuilder的创建方式：
        StringBuilder builder1=new StringBuilder();//空字符串
        StringBuilder builder2=new StringBuilder("abc");//abc串

        //String和StringBuilder互转：
        String str="abc";
        StringBuilder builder3=new StringBuilder(str);
        String str2 = builder3.toString();

         */
    }
}
